The present invention relates to a railway vehicle; and, more particularly, the invention relates to a railway vehicle which employs a bogie car. The term xe2x80x9crailway vehiclexe2x80x9d refers to a vehicle which runs on a track.
As described in Japanese application utility model publication No. Sho 58-1406, a bogie car frame and a car body of a railway vehicle are connected with a traction link (hereinafter, simply called a xe2x80x9clinkxe2x80x9d). At both ends of the link, namely in a forward and backward direction, a rubber bush is arranged. The rubber bush is designed to fully support a compression load which occurs sometimes in the forward direction and backward direction. Also, the rubber bush is used to provide running stability. In addition, the bogie car and the car body are connected by a yaw damper.
Further, a sound shielding panel using a particle-shaped member is disclosed in Japanese application patent laid-open No. Hei 10-266388. Regarding this sound shielding panel, the floor of a car body is provided in the form of an aluminum honeycomb panel, and, in an interior portion of the panel, powders having a particle size of 30 xcexcm-1000 xcexcm are provided, so that a damping of sound in an up and down direction at the floor of the car body is carried out.
A vibration in the forward direction and backward direction (relative to the running direction of the vehicle) which is generated at a bogie car side is transmitted to the two rubber bushes at the respective ends of the link, as well as through a connection portion of the yaw damper. For this reason, the noise level in the car becomes high. In particular, a solid propagation vibration having a rotation frequency component in the 80-300 Hz band area is transmitted to the bogie car and this vibration operates to vibrate the floor. Accordingly, there is a problem in that this causes an increase of the noise level in the car.
In the rotation vibration generated by an unbalance in the drive system, a noise component having a size less than 10 m/s2 from one time to three times the rotation vibration component fl of an electric motor shaft is comparatively remarkable. These rotation vibration components fl-3 fl are transmitted as a solid propagation vibration to the car body through the link, and they produce the up and down vibration of the floor of the car body, which produce noise in the car.
In particular, during an acceleration time in the car running, a two times component 2 fl is generated in the forward direction and backward direction, in the right direction and left direction, and in the upper direction and lower direction; in particular, the vibration in the forward direction and backward direction contributes to an increase in the noise level in the car. Further, during a deceleration time and a coasting time, the increase in the forward vibration and backward vibration of the component fl and three times the component 3 fl occurs remarkably. For example, when fl is 80 Hz, 2 fl is 160 Hz, and 3 fl is 240 Hz. For this reason, it is required to reduce the vibration by about more than 100 Hz.
An object of the present invention is to reduce the noise in a car by a simple construction.
The above-stated object can be attained by providing a connection member between one part of a car body and another part of the car body, or a connection body between the car body and a bogie car frame, in the form of a vessel which carries a substance which is able to move relative to the connection member. The connection members are a traction link, a yaw damper, a right and a left movement damper, provided between the car bodies ahead of and behind the damper, a bolster anchor etc.
According to the present invention, vibration energy generated at the connection member is changed to kinetic energy of the above-stated body by a collision of the above-stated substance, whereby a vibration of the connection member is reduced. For this reason, a propagation of the vibration to the car body can be restrained and the noise in the car can be reduced.
The noise in the car is generated in large part by the vibration of the floor surface of the car body. One vibration source is a rotation unbalance of the drive system of the car body. The above-stated connection member is arranged between the vibration source and the floor surface of the car body and mainly vibrates in the forward direction and back direction. For this reason, the above-stated substance in an interior portion of the connection member moves in the forward direction and backward direction. For this reason, in the movement of the substance, since it is unlikely to have a vibration of 10 m/s2 which goes against gravity, the substance moves actively relative to a small excitation force. Accordingly, the vibration source of the floor surface of the car body can be restrained, and the noise in the car can be reduced.
Since the connection member is of comparatively light weight, the vibration can be restrained by a simple apparatus.